Manufacture of water-soluble textile and other materials



Patented Aug. 31, 1954 MANUFACTURE OF WATER-SOLUBLE TEX- TILE AND OTHER MATERIALS Edgar Bert Johnson and John. Frederick Webster, Spond'on, near Derby, England, assignors to British C'cl'anese Limited, a corporation of Great Britain No Drawing. Application February 9, 1950, Serial No- 143,348

@Iaims priority; application Great Britain February 23', 1949- 8 Claims.

This invention relates to the manufacture of textile and other materials: having a basis of. a water-soluble; cellulose ether;

It; is. well known that, for, certain purposes, there is a demand for fibres and yarns, that. can be. dissolved by water, and it. is an object of the present.- invention. to. provide a practical method of. making such: fibres and yarns from waterrsoluble cellulose others; and especially from, water solublemethylcellulose;

According to; the. invention, filaments and like articles are made by extruding a spinnin solution of a water-soluble cellulose ether in. a solvent mixture.- consisting of water and a. Watermiscible. organic; liquid. or lic uids into. a. coagulating bath consisting: essentially of; an organic. liquid. or liquids. miscible all proportions with the mixture. of water an. organic liquid or liquids used.- as th solvent. in. the.- spi-nning solo:- tion.

According to the preferred form of? the inven-- tion, filaments are: made by extruding a. solution of a water-soluble cellulose ether especially a. water-soluble methyl, cellulose, in aqueous; acetic acid into anaoetone coagulating bath. Theconcentration of the. acetic. acid should. be between about 60% and 80% by volume the concentration of the methyl cellulose in. thesolution may be about. l5 %-2'5.% and. especially in theneighbourhood of The acetone. may, if desired, be employed in admixture with other liquids, e. g. with up. to an equalweight of: ethyl alcohol and/or with a smaller proportion, say up to. about 10% of its weight, of glycerol; but the best results are obtained using substantially pure acetone or acetone containing up to about 5% or- 1% of water.. Preferably both the spinning solution and the coagulating bath are at about room temperature, although. either or both can be: at a higher or lower temperature if desired.

The. tenacity of filaments so produced may be increased by stretching them, either individually or grouped together to form yarns; for example by 35%., 50%, 75% or more of their original length. Preferably the. filaments are stretched immediately after they have left the coagulating bath and while they are still wet therewith; thus on leaving the bath, the filaments may be passed in succession round two rollers, the second of which runs at a suitably higher peripheral speed than the first. Alternatively or' in addition; the filaments may be stretched in the coagulatin bath, or they may at some later stage be softened, e. g. by heating to about 290-310 C., and stretched.

2 The primary advantage of the use of aqueous acetic acid solutions of the methyl cellulose as described 13 that it, enables water-soluble yarns of good: dry tenacity to be obtained; thus yarns com prising unstretched filaments may have a tenacity in the neighbourhood of 1.0 gm. per denier and yarns comprising stretched filaments may have a tenacity about 1.25 gm. per denier; these tenaoities canont even be approached by spinning simple aqueous solutions of the methyl cellulose, for example into concentrated aqueous; salt solutions or into water-miscible organicli'quids such as. ethyl alcohol or acetone with or without a; small proportion of glycerol- A secondary but: not unimportant advantage is, as we have found, that it is considerably easier to dissolve water-soluble methyl cellulose in the aqueous acetic acidto' give a solution; substantially free from gels and fibrous ag regations and suitable for spinning than it is to dissolve the: methyl cellulose in water to give an equally satisfactory solution. It. is common knowledge that, to. obtain a clear aqueous solution. of methyl cellwlosewithin a reasonable time; it is generally necessary to adopt some: special; expedient; usually the methyl cellulose is first immersed. in andv thoroughly wetted with notv water (in which it is. ordinarily actually in.-'

soluble) and the mixture isthen cooled while stirring. In contrast to this we have found that water-soluble methyl cellulose: can readily be dissolved in the; aqueous; acetic. acid at ordinary temperatures, for example by stirring or by grinding in a ball mill or like device, and, that thESOIUIP' tions so obtained, are cruite satisfactory for spinning.

The invention is illustrated. by the: following example:-

Example A. water-soluble. methyl cellulose 0f methoxyl; content 28.0%. and; viscosity l5.3 cps. (measured in:2.% aqueoussolutionzat.20 C.) was mixed with 7M7}, or (by volume) aqueous: acetic acid in a corrosion-resistant ball; mill to: give a $0111. tion of concentration about 20%. lfhis solar-- tion. was. filtered: through. cellulosi'c tissue. and: allowed to'stand at lll" C; until it had become substantially completely de-aeratedjit was thenex:- truded. thrrrugh a jet. comprising a number of orifices of diameter 0:08 mm. into a bath of acetone at room temperature, the; filaments so formed travellin through the. bath. fora length of 48 ins. On leaving the bath, the filaments were passed in succession round two positively-driven rollers whereby they were stretched by 50% of their original length, and were then wound up as yarns, The yarns so produced were substantially completely soluble in water and had a dry tenacity of about 1.25 gm. per denier or more. When the stretching step was omitted, the tenacity was about 0.9-1.1 gm. per denier.

The process specifically described above, in which a solution of water-soluble methyl cellulose in aqueous acetic acid is extruded into a coagulating bath of acetone, is the preferred method of putting our invention into practice. It can, if desired, be modified in different ways. For example, the acetic acid can be replaced by another water-miscible organic liquid, which preferably contains one or more oxygen atoms and which has a similar or lower solvent power for the methyl cellulose or which by itself is incapable of dissolving the methyl cellulose. For instance the acetic acid may be replaced by another lower fatty acid, e. g. propionic acid; by a hydroxy compound, especially a normally liquid alcohol, e. g. methyl or ethyl alcohol; by a normally liquid hydroxy-ether, e. g. the monoethyl or other lower alkyl mono-ether of ethylene glycol; or by a normally liquid cyclic ether, e. g. dioxane; thus a spinnin solution in which the methyl cellulose is dissolved in a 70%-90% aqueous methyl or ethyl alcohol may be used. If desired two or more of the water-miscible liquids may be employed. Moreover, the acetone coagulating bath may be partly or wholly replaced by another lower aliphatic ketone such as methyl ethyl ketone or diethyl ketone, by an alcohol, especially a normally liquid aliphatic alcohol containing 5 or more carbon atoms and especially 7-10 carbon atoms, e. g. octyl alcohol, by a normally liquid hydroxy-ether, Or by two or more of these compounds. References to lower compounds or radicles are to be understood as denoting compounds or radicles containing not more than 5 carbon atoms.

Although the invention has been described with particular reference to the production of filaments and yarns from a water-soluble methyl cellulose, it may also be applied to the production of filaments and yarns from other water-soluble cellulose ethers, e. g. hydroxyethyl cellulose, carboxymethyl cellulose, or a mixed ether such for instance as hydroxyethyl ethyl cellulose or hydroxyethyl methyl cellulose. It is also of use in the production of two-dimensional shaped articles such as films and foils from the water-soluble cellulose ethers.

Having described our invention, what we desire to secure by Letters Patent is 1. Process for the production of water-soluble filaments and films, which comprises extruding a spinning solution of a water-soluble cellulose ether in aqueous acetic acid of concentration 60 to 80% by volume into a coagulating bath consisting essentially of at least one organic liquid selected from the group which consists of allphatic ketones containing at most 5 carbon atoms in the molecule, normally liquid aliphatic alcohols containing 5 to 10 carbon atoms in the molecule, and normally liquid hydroxy-ethers.

2. Process for the production of water-soluble filaments and films, which comprises extruding a spinning solution of a water-soluble methyl cellulose in aqueous acetic acid of concentration 60 to 80% by volume into a coagulating bath consisting essentially of at least one organic liquid selected from the group which consists of aliphatic ketones containing at most 5 carbon atoms in the molecule, normally liquid aliphatic alcohols containing 5 to 10 carbon atoms in the molecule, and normally liquid hydroxy-ethers.

3. Process for the production of water-soluble filaments and films, which comprises extruding a spinning solution of a water-soluble cellulose ether in an aqueous acetic acid of a concentration 60 to by volume into a coagulating bath consisting essentially of a lower aliphatic ketone.

4. Process for the production of water-soluble filaments and films, which comprises extruding a spinning solution of a water-soluble methyl cellulose in aqueous acetic acid of concentration 60 to 80% by volume into a coagulating bath consisting essentially of acetone and containing 0 to 7% of water.

5. Process for the production of water-soluble filaments and films, which comprises extruding a 15 to 25% solution of a water-soluble methyl cellulose in aqueous acetic acid of concentration 60 to 80% by volume into a coagulating bath consisting essentially of acetone and containing 0 to 7% of water.

6. Process for the production of water-soluble filaments and films, which comprises extruding a spinning solution of a water-soluble cellulose ether in an aqueous acetic acid of a concentration 60 to 80% by volume into a coagulating bath consisting essentially of a lower aliphatic ketone and stretching the products while still wet with the coagulating bath.

7. Process for the production of water-soluble filaments and films, which comprises extruding a spinning solution of a water-soluble cellulose ether in an aqueous acetic acid of a concentration 60 to 80% by volume into a coagulating bath consisting essentially of a lower aliphatic ketone and subsequently stretching the products while softened by heat.

8. Process for the production of water-soluble filaments and films, which comprises extruding a spinning solution of a water-soluble methyl cellulose in aqueous acetic acid of concentration 60 to 80% by volume into a coagulating bath consisting essentially of acetone and containing 0 to 7% of water and subsequently stretching the products while they are softened by being heated to a temperature between 290 and 310 C.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,025,730 Dickie et al Dec. 31, 1935 2,134,895 Seymour et al. Nov. 1, 1938 2,147,640 Dickie et al Feb. 21, 1939 2,163,723 Whitehead June 27, 1939 2,218,029 Hubert et al Oct. 15, 1940 2,308,141 Alles Jan. 12, 1943 2,341,586 Alles Feb. 15, 1944 2,350,161 Gloor May 30, 1944 2,495,767 Reid et al Jan. 31, 1950 FOREIGN PATENTS Number Country Date 508,547 Great Britain June 30, 1939 OTHER REFERENCES Worden, Technology of Cellulose Ethers (1933), V. 3, pages 1305 to 1308. 

1. PROCESS FOR THE PRODUCTION OF WATER-SOLUBLE FILAMENTS AND FILMS, WHICH COMPRISES EXTRUDING A SPINNING SOLUTION OF A WATER-SOLUBLE CELLULOSE ETHER IN AQUEOUS ACETIC ACID OF CONCENTRATION 60 TO 80% BY VOLUME INTO A COAGULATING BATH CONSISTING ESSENTIALLY OF AT LEAST ONE ORGANIC LIQUID SELECTED FROM THE GROUP WHICH CONSISTS OF ALIPHATIC KETONES CONTAINING AT MOST 5 CARBON ATOMS IN THE MOLECULE, NORMALLY LIQUID ALIPHATIC ALCOHOLS CONTAINING TO 10 CARBON ATOMS IN THE MOLECULE, AND NORMALLY LIQUID HYDROXY-ETHERS. 